The effectiveness of animal manure Teas on the growth of Maize(Zea Mays)

Abstract

A greenhouse experiment was conducted to evaluate the effectiveness of the newly introduced manure teas, on the growth of maize (Zea mays). Manure teas prepared from leaf or animal manure have the potential use as organic fertilizer and insecticide. But most Zambian farmers who use these teas, apply them without proper knowledge on the optimum application rate and the effects on the soil chemical and physical properties. Ten treatment combinations, (control, 15kg chicken manure (CM)/210L, 15kg cowdung (CD)/210L, 30kg CM/210L, 30kg CD/210L, 3tonnes CM/ha, 3tonnes CD/ha, 6 tonnes CM/ha, 6 tonnes CD/ha and 250kg D compound/ha) were applied to maize grown in plastic pots. The experiment was arranged as a Randomized Complete Block Design with three replications. Two crops were grown, each for a six-week period. The second crop did not receive fresh treatment application. The data collected included plant height, dry matter weight of roots and shoots, EC and pH. For the first crop, the highest dry matter production and tallest plants were with D compound fertilizer, with 23.Ig average weight per pot and 50.3cm average plant height. These were significantly higher than for the manures and the control. 15kg CM tea was best among the manxrres, with 13.4g average weight per pot. Solid manure treatments were only slightly but not significantly better than the control. The residual effects of 15kg and 30kg CM were highest with 14.23g and 13.63g average weight per pot of dry matter production. Generally, soil EC values were increased by all treatments during the first cropping with 15kg and 30kg CM tea manure ranking highest (3.15 and 6.24mS/cm) compared to the control (0.91mS/cm). All EC values were reduced during the second cropping, to an average of 1.0 mS/cm. The tea manures also raised the soil pH. 15 kg CM was found to be as effective as 30 kg CM, since there was no significant difference observed on the effects of most measured parameters. 15kgCM or CD was proved to be economical compared to 30kg CM or CD (usual rate applied by Zambian farmers), as less manure quantities are used.